This invention relates to a method and apparatus for dispersing fiber clumps, e.g. cotton boll clumps, from two or more textile fiber modules, e.g. cotton boll modules, at the same time, and mixing the clumps to form a blend, and to a method and apparatus for mixing particulate materials, e.g. wood chips.
Below there is a description of the handling of cotton fibers, starting with the harvesting of cotton bolls. However, the invention is not limited to the handling of cotton fibers but rather applies equally as well to the handling of other textile fibers that have been compressed into large modules that need to be mechanically dispersed into clumps of fibers so that the fibers can be separated, cleaned and then further processed, ultimately into yarns. It also applies to mixing particulate materials, e.g. wood chips.
As known to those skilled in the art, cotton plants produce seedpods, known as cotton bolls, which contain the seeds. Seed hairs, or fibers, growing from the outer skin of the seeds, become tightly packed within the boll, which bursts open upon maturity, revealing soft masses of the fibers. These fibers are white to yellowish white in color, range from about 0.75 to about 1.5 inches in length and are composed of about 85-90% cellulose, a carbohydrate plant substance; five to eight percent water; and four to six percent natural impurities.
Cotton is harvested when the bolls open. In the fields, the cotton bolls are tightly compressed into large modules which are transported from the fields to processing plants. In the processing plants, the modules are mechanically dispersed into clumps of bolls and then the fibers are separated from the seeds and are cleaned and then are further processed, ultimately into yarns.
It is known to disperse the cotton boll modules by use of a stack of rolls that include fingers which rotate into an advancing end of a cotton module, to tear loose clumps of the bolls from the module as they rotate. The stack of rolls is termed a disperser and it is common to use conveyors for delivering the cotton modules to the disperser. Example disperser systems are disclosed by the following United States Patents: U.S. Pat. No. 4,497,085, granted Feb. 5, 1985 to Donald W. Van Doorn, James B. Hawkins, Tommy W. Webb and William A. Harmon, Jr.; U.S. Pat. No. 5,121,841, granted Jun. 16, 1992, to Keith Harrington and Donald Rogers; U.S. Pat. No. 5,222,675, granted Jun. 29, 1993, to Jimmy R. Stover; U.S. Pat. No. 5,340,264, granted Aug. 23, 1994, to Manfred W. Quaeck and U.S. Pat. No. 5,469,603, granted Nov. 28, 1995, to Jimmy R. Stover. These patents show examples of the conveyors which have been used, or proposed, for delivering the cotton modules to the disperser. The present invention is not limited to any particular type of conveyor. However, a reciprocating slat conveyor is preferred. Example reciprocating slat conveyors that are suitable are disclosed by U.S. Pat. No. 5,934,445, granted Aug. 10, 1999, to Raymond Keith Foster, Randall M. Foster and Kenneth A. Stout, and U.S. Pat. No. RE 35,022, granted Aug. 22, 1995, to Raymond Keith Foster.
Cotton fibers, for example, may be roughly classified into three main groups, based on staple length (average length of the fibers in a cotton module) and appearance. The first group includes the fine, lustrous fibers with staple length ranging from about 1 to about 2.5 inches and includes types of the highest qualityxe2x80x94such as Sea Island, Egyptian and Pima cottons. Least plentiful and most difficult to grow, long-staple cottons are costly and are used mainly for fine fabrics, yarns and hosiery. The second group contains the second group contains the standard medium-staple cotton, such as American Upland, with staple length from about 0.5 to 1.3 inches. The third group includes the short-staple, coarse cottons, ranging from about 0.375 to 1 inch in length, used to make carpets and blankets, and to make coarse and inexpensive fabrics when blended with other fibers. Within each group, the quality of the fibers can vary depending on such things as where the cotton is grown. It is desirable to blend the lower quality fibers with higher quality fibers to produce an acceptable quality blend of fibers. It is an object of the present invention to provide a method and apparatus for blending cotton clumps as they are removed from the cotton modules. The clumps of bolls are mixed together to form the blend and then the blend is further processed to separate the fibers from the seeds, etc.
Another object of the present invention is to provide a method and apparatus for blending other types of textile fiber clumps as they are removed from the textile fiber modules. Clumps from different modules are mixed together to form a blend of the fibers and then the blend is conveyed on for further processing.
It is yet another object of the invention to provide a method and apparatus for mixing particulate materials, such as different types and/or grades of wood fiber chips, and wood fiber chips with other materials, e.g. granule recycled plastic.
One apparatus of the present invention is basically characterized by a pair of confronting dispersers, each having an input side and an output side. The output sides of the two dispersers face each other on opposite sides of a mixing zone. A feed conveyor is provided for each disperser. Each feed conveyor is adapted to feed textile fiber modules into the input side of its disperser. An output conveyor is positioned between the two dispersers, at the bottom of the mixing zone. The feed conveyors are adapted to move the modules to the dispersers. Each disperser removes fiber clumps from its module and discharges them airborne into the mixing zone into admixture with fiber clumps delivered airborne into the mixing zone from the other disperser. The mixed blend of fiber clumps falls on the outfeed conveyor and the output conveyor carries the blend away from the mixing zone.
Each disperser comprises a plurality of power driven rolls, each of which is supported for rotation about a horizontal axis and includes a plurality of fingers that move into and then out from the module as the rollers rotate. The fingers are adapted to remove fiber clumps from the module and project them into the mixing zone.
Preferably, the output conveyor extends generally perpendicular to the two feed conveyors. Preferably also, the feed conveyors are reciprocating slat conveyors. The outfeed conveyor may be an endless belt conveyor.
According to an aspect of the invention, the apparatus may comprise first and second pairs of confronting dispersers of the type described, each disperser having its own feed conveyor. The output conveyor picks up a blend of fiber clumps from the first mixing zone and moves the blend onto the second mixing zone where a second blend of fibers and fiber clumps is deposited onto the cotton boll clump already on the output conveyor.
The method of the present invention is basically characterized by positioning first and second dispersers at a disperser station, in a spaced apart confronting relationship, so as to define a mixing zone between them. The first and second dispersers are operated while a first module is fed into the first disperser and a second module is fed into the second disperser. The first and second dispersers are operated so that each will disperse fiber clumps from its module and deliver them into the mixing zone in admixture with the fiber clumps from the other disperser. The mixture of fiber clumps is collected at the bottom of the mixing zone and is carried away from the disperser station.
Another aspect of the invention is to feed the modules against the dispersers by use of conveyors and controlling the feed rate by controlling the conveyor speed.
A further aspect of the invention is to provide third and fourth dispensers at the dispenser station, also in a spaced apart confronting relationship, so as to define a second mixing zone between them. The third and fourth dispersers are operated while a third textile fiber module is fed into the third disperser and a fourth textile fiber module is fed into the fourth disperser. The third and fourth dispersers are operated so that each will disperse fiber clumps from its module and deliver them into the second mixing zone in admixture with the fiber clumps from the other disperser of the pair. The mixture of fiber clumps is collected at the bottom of the second mixing zone, on top of the mixture of fiber clumps from the first mixing zone, and the total mixture is carried away from the disperser station.
Yet another aspect of the invention is to provide an improved disperser roll construction. According to this aspect of the present invention, the disperser roll is provided with an elongated tubular core. At least two axially spaced apart disks are provided in the tubular core. A plurality of elongated tooth support members are spaced around the tubular core. Each tooth support member has an inner portion contacting the core and an outer portion spaced radially outwardly from the core. Each tooth support member is connected to the spaced apart radial disks. A plurality of generally radially outwardly extending teeth are secured to the outer portion of each tooth support member.
Preferably, each tubular core has opposite ends and the disperser roll has support shafts projecting outwardly from the opposite ends of the tubular core.
Preferably also, the disperser roll has at least three axially spaced apart radial disks on the tubular core, dividing the core into at least two axial sections. The elongated tooth support members for each section are spaced angularly in position relative to the tooth support members for the other section.
In preferred form, the disperser roll comprises four axially spaced apart radial disks on the tubular core, dividing the core into three axial sections. The elongated tooth support members for each section are angularly spaced in position from the tooth support members of the adjacent section.
In preferred form, the teeth are detachably secured to the outer portions of the tooth support members. Also, in preferred form, the elongated tooth support members are angle iron members. The inner portion is an inwardly extending first leg of the angle iron member and the outer portion is chordwise extending second leg of the angle iron member.
A still further aspect of the invention is to provide a system which includes two dispersers in a disperser tunnel or four dispersers in two disperser tunnels, and a feed conveyor for each disperser that is at the bottom of an elongated storage bin for a particulate material, e.g. wood chips or the like. In use, the conveyors feed the particulate material to the dispersers. The disperser of each pair picks up particles from the particulate material in its bin and propels them towards the other disperser. The particles from the two dispersers meet and mix within a mixing zone that is located between the dispersers. An outfeed conveyor at the bottom of the mixing zone collects the mixed particles and removes them from the disperser station.
Other objects, advantages and features of the invention will become apparent from the description of the best mode set forth below, from the drawings, from the claims and from the principles that are embodied in the specific structures that are illustrated and described.